US4414069A
Expired / Lapsed
US
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Negative ion beam selective etching process
Assignee: International Business Machines Corp
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Filing: 1982-06-30
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Granted: 1983-11-08
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Expires: 2002-06-30
Abstract
Abstract A negative ion etching process is described for etching a substrate, where the negative ions are sputtered from a target by a sputtering gas. The negative ions are released from the target and are accelerated toward the substrate, which they strike as either negative ions or energetic neutrals. The improvement adds an inhibiting substance (hydrogen) to the sputtering gas to dramatically affect the etch rates of the substrate. In one example, the ratio of the etch rates of Si and SiO2 are changed by large amounts by the addition of hydrogen to a sputtering gas comprising an inert species, such as argon.
Inventors
- 👤 Jerome J. Cuomo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:22
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
44 words
In a negative ion etching process, wherein negative ions are sputtered from a target by a sputtering plasma and then are accelerated to a substrate to cause etching therefrom, the improvement wherein hydrogen or a species containing hydrogen is added to said sputtering plasma.
Claim 2
Dependent Claim
44 words
In a negative ion etching process, wherein negative ions are sputtered from a target by a sputtering plasma and then are accelerated to a substrate to cause etching therefrom, the improvement wherein hydrogen or a species containing hydrogen is added to said sputtering plasma.
Claim 3
Dependent Claim
23 words
The process of claim 1, wherein said negative ions for etching are selected from the group consisting of F, Cl, Br, and I.
Claim 4
Dependent Claim
11 words
The process of claim 2, wherein said substrate is a semiconductor.
Claim 5
Dependent Claim
11 words
The process of claim 2, wherein said substrate is an insulator.
Claim 6
Dependent Claim
11 words
The process of claim 2, wherein said substrate is a metal.
Claim 7
Dependent Claim
16 words
The process of claim 2, wherein said substrate includes layers of Si and SiO 2 .
Claim 8
Dependent Claim
21 words
The process of claim 2, wherein said substrate includes layers of Si, SiO 2 , and Si 3 N 4 .
Claim 9
Dependent Claim
18 words
The process of claim 1, wherein said substrate is at a positive potential with respect to said target.
Claim 10
Dependent Claim
13 words
The process of claim 1, wherein said sputtering plasma includes an inert gas.
Claim 11
Dependent Claim
18 words
The process of claim 1, wherein said target, substrate, and said plasma are contained in a vacuum chamber.
Claim 12
Dependent Claim
12 words
The process of claim 1, wherein said target is an ionic compound.
Claim 13
Dependent Claim
75 words
A process for etching a substrate, comprising the steps of: directing a plasma including a sputtering species and hydrogen to a target held at a negative potential V T with respect to ground to release negative ions therefrom, and accelerating said negative ions to said substrate to etch said substrate, said substrate having a small negative potential V B with respect to ground and including layers of different materials, wherein |V T |>|V B |.
Claim 14
Dependent Claim
75 words
A process for etching a substrate, comprising the steps of: directing a plasma including a sputtering species and hydrogen to a target held at a negative potential V T with respect to ground to release negative ions therefrom, and accelerating said negative ions to said substrate to etch said substrate, said substrate having a small negative potential V B with respect to ground and including layers of different materials, wherein |V T |>|V B |.
Claim 15
Dependent Claim
16 words
The process of claim 12, where said substrate includes layers of Si and SiO 2 .
Claim 16
Dependent Claim
14 words
The process of claim 12, wherein said substrate includes Al 2 O 3 .
Claim 17
Dependent Claim
12 words
The process of claim 12, where said substrate includes an oxide layer.
Claim 18
Dependent Claim
17 words
The process of claim 12, where said substrate includes a layer of Si 3 N 4 .
Claim 19
Dependent Claim
12 words
The process of claim 12, where said plasma includes argon and hydrogen.
Claim 20
Dependent Claim
12 words
The process of claim 12, where said target is an ionic compound.
Claim 21
Dependent Claim
21 words
The process of claim 12, where said negative ions are selected from the group consisting of F, Cl, Br, and I.
Claim 22
Dependent Claim
25 words
The process of claim 12, wherein said substrate includes layers of Si and SiO 2 , and said plasma is comprised of argon and hydrogen.
Claim 23
Dependent Claim
41 words
The process of claim 12, wherein said substrate includes a first layer which has an etch rate that increases when hydrogen is added to said plasma and a second layer whose etch rate decreases when hydrogen is added to said plasma.
Claim 24
Dependent Claim
79 words
A process for etching a substrate, comprising the steps of: producing negative ions by RF sputtering of a target by a plasma including an inhibiting gas, accelerating said negative ions from said target to a substrate having at least two layers of different materials, for etching said materials, said inhibiting gas causing the enhancement of etch rate of one of said materials in said substrate and inhibiting the etch rate of the other of said materials in said substrate.
Claim 25
Dependent Claim
79 words
A process for etching a substrate, comprising the steps of: producing negative ions by RF sputtering of a target by a plasma including an inhibiting gas, accelerating said negative ions from said target to a substrate having at least two layers of different materials, for etching said materials, said inhibiting gas causing the enhancement of etch rate of one of said materials in said substrate and inhibiting the etch rate of the other of said materials in said substrate.
Claim 26
Dependent Claim
13 words
The process of claim 22, wherein said substrate has an electrical bias thereon.
Claim 27
Dependent Claim
19 words
The process of claim 23, wherein said layers in said substrate are layers of Si and SiO 2 .
Claim 28
Dependent Claim
11 words
The process of claim 24, where said inhibiting gas is hydrogen.
Claim 29
Dependent Claim
21 words
The process of claim 25, wherein said negative ions are selected from the group consisting of F, Cl, Br, and I.
Claim 30
Dependent Claim
16 words
The process of claim 23, where said substrate includes a semiconductor layer and an insulating layer.
References Cited (Backward Citations)
US4132614A
Cited
US4250009A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1986-11-07 | 1987-05-09 | 1987-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-07 | 1991-05-09 | 1991-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-07 | 1995-05-09 | 1995-11-08 | $7700.00 | Window Closed / Lapsed |